Engineers at the University of Pittsburgh (PITT) are leading a national research effort to utilise additive manufacturing in developing stronger coatings for materials used in harsh environments, such as the super-heated interior of a gas turbine.

Minking Chyu, PhD, Professor of Mechanical Engineering and Materials Science at the University of Pittsburgh. Source: PITT

Minking Chyu, PhD, the Leighton and Mary Orr Chair Professor of Mechanical Engineering and Materials Science at the University of Pittsburgh, will lead the researchers, who received a cooperative agreement from the Department of Energy's National Energy Technology Laboratory (NETL). His team received funding through the University Turbine Systems Research Program - a branch of the Department of Energy's signature Advanced Turbines program.

Protection for materials exposed to itense heat

One of only nine projects selected nationwide, this project (Design, fabrication, and performance characterisation of near-surface embedded cooling channels with an oxide dispersion strengthened coating layer) plans to improve thermal protection for materials exposed to intense heat in modern and future gas turbines.

Chyu will make use of an oxide dispersion strengthened (ODS) coating layer with embedded cooling channels beneath or within the ODS layer to achieve a process called near-wall cooling. The project will employ rapidly advanced additive manufacturing (AM) processes-a more accurate way to describe the professional production technique commonly referred to as "3D printing."

Innovative approach

Apart from significant cost reduction in raw materials, AM offers enormous design freedom and an innovative approach compared to conventional techniques, which imposed certain limitations in having the ODS layer atop of the turbine components.

"Even though ODS has many superb properties for protecting substrate material from oxidation and deteriorated strength in a very high temperature environment, it is very hard for traditional machining or cutting," said Chyu. "Therefore, this technology would not be realizable if not because of AM."